Environmental protection measures increasingly necessitate the avoidance of organic solvents in chemical formulations. Aqueous systems are accordingly being used more and more.
Aqueous dispersions of organopolysiloxanes are well known in the art. For example, aqueous silicone dispersions containing hydroxylated diorganopolysiloxanes, colloidal silicon dioxide and an organic amine or sodium hydroxide are described in U.S. Pat. No. 4,221,688 (R. D. Johnson, Dow Corning Corp.; issued Sep. 9, 1980).
Aqueous silicone dispersions which are obtained by adding an alkali metal silicate to an anionically stabilized aqueous emulsion of a polydiorganosiloxane containing hydroxyl end groups are described in U.S. Pat. No. 4,244,849 (J. C. Saam, Dow Corning Corp.; issued Jan. 13, 1981). Aqueous dispersions which contain siliconates in addition to the polydiorganosiloxanes containing hydroxyl groups in the terminal units and (organo)metallic compounds are described in U.S. Pat. No. 4,816,506 (N. Gamon, Wacker-Chemie GmbH; issued Mar. 28, 1989) as well as U.S. Pat. No. 5,045,231 (R. Braun, Wacker-Chemie GmbH; issued Sep. 3, 1991) and corresponding DE 39 32 025 A (published on Apr. 4, 1991).
Therefore, it is an object of the present invention to provide aqueous organopolysiloxane dispersions which are stable over long periods of time. Another object of the present invention is to provide aqueous organopolysiloxane dispersions which can be used without a long storage time. A further object of the present invention is to provide aqueous organopolysiloxane dispersions which can be used to prepare elastomers.